FINGER VASOMOTOR, HEART RATE, AND ELECTRODERMAL MEASURES OF ORIENTING AND DEFENSIVE REFLEXES

Abstract

The present study was carried out to differentiate orienting reflexes (OR) from defensive reflexes (DR) using 20 female college students as Ss. All Ss received 5 stimulations of 1sec weak tone (1000Hz, 40dB) and 5 stimulation of 1sec strong tone (white noise, 100dB) in a randomized order and time interval. Finger pulse amplitude (PA), finger blood content (BC), heart rate (HR), and palmar skin potential reflex (SPR) were recorded simultaneously. BC decrease, HR deceleration, and negative wave of SPR occurred to weak stimulations, while increase, acceleration, and positive wave occurred to strong stimulations. Both intensities of stimulation produced a decrease in PA. These results were discussed in relation to the autonomic changes involved in OR and DR.